Abstract: A general purpose computer is programmed to provide graphic representations of the mechanical and electrical systems of an operating plant where all of the components are treated as "objects" and associated through a relational database with text files providing component specifications, product identifications, component operating status, and all directly interconnected components including data as to flow direction and relative position in the system. For maintenance and service each component is associated with existing and future specified work orders, service requirements including consideration of probable life expectancy and the like.

Abstract: A manually steerable machine for scabbling areas which are relatively inaccessible to larger machines is disclosed. Three pneumatically operable piston and cylinder assemblies with bits are mounted on a plate which is mounted in vertically movable relationship on a frame, the assemblies being disposed at the apices of a triangle, one of the apices being at the forward end of the frame and the other apices being rearwardly of the one of the apices. A tiltable handle extends from the rear end of the frame and upwardly from the frame and includes an air manifold and an air valve for supplying compressed air to the assemblies through hoses. A pair of wheels at the rear of the frame support the frame when the pistons are not operating. A skid plate is attached to the bottom of the frame, and the bits are encircled by a flexible skirt extending downwardly from the frame. A vacuum hose connector has its lower end at the bottom of the frame and between the bits to collect dust.